KNOXVILLE - Knoxville police are keeping their eyes out for a dangerous and deadly drug. It looks like a chunk of concrete, can kill with one dose, and is being called 'Gray Death.'

So far, it's been found in Ohio, Georgia, and Kentucky, which are all states connected to Tennessee by an interstate.

According to reports, the drug is 10,000 times more potent than morphine, 100 times more powerful than fentanyl, and includes an elephant tranquilizer called Carfentanil.

That tranquilizer showed up in Tennessee for the first time this year. Since then, it's been found in five separate cases, including one in East Tennessee.

Knoxville Police Chief David Rausch said he is concerned about the new drug concoction.

"It's just another leg in this ongoing battle. We're seeing all these derivatives of fentanyl, and now we're seeing this," said Rausch. "There's chemical compounds in this that are very dangerous."

The Tennessee Bureau of Investigation is urging local law enforcement to handle opioid evidence differently because of Carfentanil. A person can overdose just by touching the tranquilizer. TBI officials are asking lab workers to double bag all evidence that could contain the drug.

Knoxville police say they are aware of the drug and are watching out for it. In the meantime, officers say treatment is key to addiction. They are urging all addicts to reach out to police for help.